diff --git a/Source/cmOrderDirectories.cxx b/Source/cmOrderDirectories.cxx
index 7744a5a82c80097264d1343d6d71caf19c1cdaf8..d48eb53a3fe5ee067a87a07742b1d0673d8db1ee 100644
--- a/Source/cmOrderDirectories.cxx
+++ b/Source/cmOrderDirectories.cxx
@@ -287,8 +287,7 @@ void cmOrderDirectories::AddRuntimeLibrary(std::string const& fullPath,
         }
       }
 
-      if (this->ImplicitDirectories.find(dir) !=
-          this->ImplicitDirectories.end()) {
+      if (this->IsImplicitDirectory(dir)) {
         this->ImplicitDirEntries.push_back(
           new cmOrderDirectoriesConstraintSOName(this, fullPath, soname));
         return;
@@ -316,8 +315,7 @@ void cmOrderDirectories::AddLinkLibrary(std::string const& fullPath)
     // Implicit link directories need special handling.
     if (!this->ImplicitDirectories.empty()) {
       std::string dir = cmSystemTools::GetFilenamePath(fullPath);
-      if (this->ImplicitDirectories.find(dir) !=
-          this->ImplicitDirectories.end()) {
+      if (this->IsImplicitDirectory(dir)) {
         this->ImplicitDirEntries.push_back(
           new cmOrderDirectoriesConstraintLibrary(this, fullPath));
         return;
@@ -347,7 +345,18 @@ void cmOrderDirectories::AddLanguageDirectories(
 void cmOrderDirectories::SetImplicitDirectories(
   std::set<std::string> const& implicitDirs)
 {
-  this->ImplicitDirectories = implicitDirs;
+  this->ImplicitDirectories.clear();
+  for (std::set<std::string>::const_iterator i = implicitDirs.begin();
+       i != implicitDirs.end(); ++i) {
+    this->ImplicitDirectories.insert(this->GetRealPath(*i));
+  }
+}
+
+bool cmOrderDirectories::IsImplicitDirectory(std::string const& dir)
+{
+  std::string const& real = this->GetRealPath(dir);
+  return this->ImplicitDirectories.find(real) !=
+    this->ImplicitDirectories.end();
 }
 
 void cmOrderDirectories::SetLinkExtensionInfo(
@@ -394,8 +403,7 @@ void cmOrderDirectories::AddOriginalDirectories(
   for (std::vector<std::string>::const_iterator di = dirs.begin();
        di != dirs.end(); ++di) {
     // We never explicitly specify implicit link directories.
-    if (this->ImplicitDirectories.find(*di) !=
-        this->ImplicitDirectories.end()) {
+    if (this->IsImplicitDirectory(*di)) {
       continue;
     }
 
diff --git a/Source/cmOrderDirectories.h b/Source/cmOrderDirectories.h
index 90a67e7dfa802826a0c02a1a7c571d574ee70d2c..d9e01269f5493dd2b93ad4b6df75e55580b79a0c 100644
--- a/Source/cmOrderDirectories.h
+++ b/Source/cmOrderDirectories.h
@@ -82,6 +82,8 @@ private:
   // Compare directories after resolving symlinks.
   bool IsSameDirectory(std::string const& l, std::string const& r);
 
+  bool IsImplicitDirectory(std::string const& dir);
+
   std::string const& GetRealPath(std::string const& dir);
   std::map<std::string, std::string> RealPaths;